It is not easy to put our thoughts into words. It often takes several revisions before we can express ourselves clearly. One of the reasons for this is because there is an interaction between writing and thinking. As we struggle to put our thoughts into words, we are actually thinking. Our thoughts could even be changing. Once we see what we think we want to say in words, we might even want to change it. The section Writing is a Process explains the process along with strategies for thinking about a topic and forming ideas to write about.
It is not enough to simply have ideas and create clear sentences. Those sentences are part of a larger writing. There are various types of writings such as a business memo or letter, a journal, a newspaper article, or even a novel. Paragraphs and Essays focuses on the development of a paragraph which can be applied to most types of writing and the organization of an academic essay. There has to be a logical flow within a paragraph and within a larger writing such as an essay. Transitions can help connect sentences for a smooth flow. In addition, any writing must maintain a focus on the point. Unity and Coherence in Essays explains these necessary components and how to achieve them.
The section on Critical Thinking explains how logical thinking works and describes different types of fallacies in logic (logical fallacies). Not only must the sentences have a logical flow, but there must be an overall sound reasoning to the paper to persuade the reader. Appropriate language is necessary as well.